Martin Luther King Jr. has his own national holiday, but when people celebrate his life and contributions to the civil rights movement, his 1963 March on Washington—which included his “I Have a Dream” speech—receives the lion’s share of the attention. While that majestic speech rightfully deserves praise, it lives forever as an aspiration, hovering above the actual struggle that defined King’s achievements. The film Selma, which opened in a few theaters on Dec. 25 and will expand wide on Jan. 9, examines one of the most tense and pivotal moments in King’s life and the civil rights movement: the proposed march from Selma, Ala., to the state capitol of Montgomery to protest the systematic disenfranchisement and intimidation of African-Americans in the South.

Though blacks had legally had the right to vote since the 15th Amendment became law after the Civil War, Jim Crow laws and segregationist Southern-state governments had put up barriers to minorities who tried to register to vote. In 1965, after King and his Southern Christian Leadership Conference arrived in Selma to publicize the disgraceful situation, he took out an ad in The New York Times after he’d been arrested that said, “There are more Negroes in jail with me than there are on the voting rolls.” In a county where more than half the population was African-American, that was unacceptable, and Selma became the chosen flashpoint because King and other protestors knew that the local sheriff was a racist bully who would give them the violent confrontation that was tragically required to jolt the American consciousness.

Director Ava DuVernay focused her film on King and the men and women who literally risked their lives by walking across the Edmund Pettus Bridge and were greeted by state troopers who viciously bludgeoned them while TV cameras captured it all. In an exclusive behind-the-scenes featurette about the film and the actual history, men like Andrew Young and John Lewis who were there, as well as the cast and crew, discuss the importance of bringing a film about Selma and King to the screen in 2014.